You currently have javascript disabled. Several functions may not work. Please re-enable javascript to access full functionality.

Welcome to the eG Forums!

These forums are a service of the Society for Culinary Arts & Letters, a 501c3 nonprofit organization dedicated to advancement of the culinary arts. Anyone can read the forums, however if you would like to participate in active discussions please join the society.

I was wondering if anyone else has tried making Heston Blumenthal's exploding chocolate cake. One of the ingredients in the crust is "popping sugar", which is basically unflavored poprocks. My understanding is that the chemical reaction that releases the C02 from the sugar is caused when water is introduced, and that the sugar is stable in a fat mixture. However, as soon as I added the mixture to the crust it started popping away... I added some extra sugar on top of the crust, but when I added the chocolate, it started popping again...... I'm a bit worried that I'm going to miss out on this special effect.

I have not made the exploding chocolate cake, but I did use Heston's recipe for a popping candy dacquoise from the Fat Duck Cookbook, which is similar in principle.

The popping candy I used was coated in cocoa butter, and specifically designed to be cooked with (and not eaten directly). If you have used pop rocks or space dust or something from a supermarket then it might not work as well. The cocoa butter coating helps to stop the bits melting prematurely, but the trick is not to heat up your mixture so the cocoa butter melts, or the popping candy melts, and not to press it too firmly (crushing it makes it pop).

I used Molecule-R's neutral popping candy, which I surprisingly found at bulk barn.

Next time, I think I will put the crust mixture in the fridge for a bit before adding the popping sugar. This should give time for the melted butter to solidify again, and hopefully not interact with the popping sugar.

Heat and moisture set off the popping candy. From the sounds of it the chocolate may have been too warm when you added it to the mix. I've found its best if the chocolate is appox body temp (ie: dip your finger in and it should feel the same temp as your finger.) when you add it the mix with the popping candy.

I've made several popping candy bases this way and haven't had a problem with the candt "pre-popping" so to speak.

I just made it this week for my sister-in-law's birthday. This was done entirely on a whim, so I ended up buying cotton candy pop rocks (gasp!) and using them instead of the unflavored ones. It worked.

When I crushed the biscuits, and added the sugar and butter, I waited a bit so the butter was entirely absorbed by the biscuits and it was cooled off. I mixed the pop rocks in half of the biscuit crumbs, patted it into the pan, then sprinkled on some extra pop rocks (entirely for fun), and then sprinkled more crumb/butter mixture on top- just to make sure the rocks were sealed in there nice and securely. I just put it in the fridge while I finished getting the chocolate mixture ready.

Then, I spread some cooled chocolate mixture over it, froze it, and then finished the rest of the steps. I flocked it using my Wagner paint sprayer, thinned the chocolate with coconut oil. Garnished with dark chocolate curls that I brushed with hot pink lustre dust.

The other departure from the recipe was using raspberry puree instead of passionfruit. We don't seem have them available where I live. (Plus, my SIL LOVES chocolate and raspberry.)

The look on her face was priceless when she took her first bite of it, and started popping like mad in her mouth. Totally worth the work and the mess, IMHO. :+)

I made a variation as a birthday cake and it came out great. Mine was just the exploding crust, raspberry filling, and chocolate ganache on top. Techincally it was a truffle tart (someone suggested I call it a pop tart).

To keep the pop rocks from pre-exploding, I modified the recipe to use brown butter (cooks off the water, and tastes amazing). I dispensed with browning the shortbread cookies, because the ones I got were nicely browned already, and I'd be getting plenty of toasted flavor from the butter.

I also put a barrier layer of chocolate over the crust. This was dark chocolate, melted, and with a little butter swirled in for pliability.

The raspberries where cooked on low heat until soft. Then I strained out the juices, reduced them, and thickened with a bit of xanthan and arrowroot starch (pectin would probably work also, but I was on vacation and these were the thickeners I'd brought along).

The ganache on top was just 50/50 dark chocolate and cream. I considered putting the raspberries on top, but the chocolate top let me make a stencil and dust with cocoa powder.

Despite the thickening, some raspberry juice oozed out of the springform pan while setting up in the fridge. But it didn't soak the base. There was plenty of popping. Even two days later the last of the leftovers had some pop left.

In the future I might up the proportion of popping candy (I got the stuff from Molecular Recipes). This was more of a crackling cake than an exploding one.

Is the cake or tart recipe in a book? If so, which one? (I don't have any of his books. Yet.) We do a chocolate caramel tart (choc pate sucree, layer of caramel, topped with ganache) and it would be nice to have a fun variation on that kind of truffle tart.

Is the cake or tart recipe in a book? If so, which one? (I don't have any of his books. Yet.) We do a chocolate caramel tart (choc pate sucree, layer of caramel, topped with ganache) and it would be nice to have a fun variation on that kind of truffle tart.